Your idea would make sense if RISC OS was still a thriving market with all of the key pieces of software actively developed. Sadly, it isn't.
As has already been pointed out, Castle appear to have considered including this kind of check in RO5 and ruled it out because it would have broken everything; if they felt that four years ago, the situation is even worse now.
Having such a check makes a lot of sense, and in some situations it is nearly essential. I can fully understand why it has been included, as OEM customers are likely to consider the lack of it a show-stopper. But, for desktop systems, it has come too late. By all means include it, and allow savvy users to turn it on if they understand the consequences -- but don't ship it on by default.
And *in* *particular*, don't ship it on by default having failed to tell what remains of the developer community about it (the app note doesn't count: it had been ignored for ten years, so there should at least have been an announcement to the effect of "we're now going to implement this in a few months' time"). That is what is really getting up people's noses from what I can see. That and people claiming that trying to get dead software, for which a proper update isn't likely to happen, around the tests is "subversive" and "working against ROL".
It's another PR own goal by ROL, and coming on the heels of similar problems in the past, it doesn't give a good impression -- whatever good intentions may have been behind the changes. And given the entrenched views of so many people in this market now, it's the *impressions* that matter.
Principles are great, but they're also going to deny A9 users access to a lot of old software (and potentially support for new software, if developer goodwill is lost) unless we're very careful.